But even shorts, assuming they're like reels/stories, the "social" aspect is very minimal compared with, say, Facebook posts back in the day, where your friends would see and comment and reply to each other.

The Algorithm doesn't really want that anymore; it wants to feed you content from arbitrary people to keep you passively engaged, not to foster conversation/active engagement.

But if the 99% garbage is the price of the emerging of channels like 3B1B, I think it's still a pretty good deal.